Claude, I keep going back to the GMC engine and all the similarities it shares with the Stovebolt. If you saw the two of them a few feet apart with only the long blocks being visible, at first blush one would have to study them over a bit to tell which was which. Especially if the GMC engine didn't have the valve cover on it that says "GMC". I've ported a few GMC heads for some nostalgia racer guys and they have done some impressive things with them. The same mods performed to a Stovebolt head just wouldn't yield near the same results.
So my solution would be to blend the better attributes of the GMC head, which would be its intake and exhaust ports, and merge them with the Stovebolt head footprint yielding the same Stovebolt look, and allowing it to retain the common intake, exhaust and valve cover it already has. Then tweak the chamber design and voila!
That would be my plan of attack initially, and if any revisions need to be made afterward, then they would be addressed at that time to fine tune the design.
So back to your original question about the point at which you loose the Stovebolt look. From the aesthetic standpoint, a head with the GMC ports in it will fool anyone looking at it, other than the fact its aluminum. For those seeking to go above and beyond and desire a 12 Port head, then maybe at that point you will lose some of the nostalgic look of it because you will then have a crossflow design head and more racy looking accessories that may stray from the original. So maybe at that point it will.
